Boundary Layers: Glossary

Key Points

Boundary Layer thickness
  • The boundary layer grows the fastest in case (b)

  • The boundary layer grows half as fast in case (c)

  • The boundary layer grows the slowest in (a)

Transition To Turbulence
  • The Reynolds number at which transition occurs is at \(3.2\times10^5\)

  • For the above problem the transition distance is 11cm.

  • The boundary layer height at this distance is 0.1cm.

Helicopter On Mars
  • Firstly we explored the relationship between lift and drag for various angles of attack.

  • The lift and drag force we refer to here are a result of pressure drag.

  • The total drag is a combination of pressure drag and viscous drag.

  • We used the relationship between Cl/Cd to calculate the drag and power consumption of Ingenuity

Glossary

0-based indexing
is a way of assigning indices to elements in a sequential, ordered data structure starting from 0, i.e. where the first element of the sequence has index 0.
CSV (file)
is an acronym which stands for Comma-Separated Values file. CSV files store tabular data, either numbers, strings, or a combination of the two, in plain text with columns separated by a comma and rows by the carriage return character.
database
is an organized collection of data.
dataframe
is a two-dimensional labeled data structure with columns of (potentially) different type.
data structure
is a particular way of organizing data in memory.
data type
is a particular kind of item that can be assigned to a variable, defined by by the values it can take, the programming language in use and the operations that can be performed on it.
dictionary
is an unordered Python data structure designed to contain key-value pairs, where both the key and the value can be integers, floats or strings. Elements of a dictionary can be accessed by their key and can be modified.
docstring
is an optional documentation string to describe what a Python function does.
faceting
is the act of plotting relationships between set variables in multiple subsets of the data with the results appearing as different panels in the same figure.
float
is a Python data type designed to store positive and negative decimal numbers by means of a floating point representation.
function
is a group of related statements that perform a specific task.
integer
is a Python data type designed to store positive and negative integer numbers.
interactive mode
is an online mode of operation in which the user writes the commands directly on the command line one-by-one and execute them immediately by pressing a button on the keyword, usually Enter.
join key
is a variable or an array representing the column names over which pandas.DataFrame.join() merge together columns of different data sets.
library
is a set of functions and methods grouped together to perform some specific sort of tasks.
list
is a Python data structure designed to contain sequences of integers, floats, strings and any combination of the previous. The sequence is ordered and indexed by integers, starting from 0. Elements of a list can be accessed by their index and can be modified.
loop
is a sequence of instructions that is continually repeated until a condition is satisfied.
NaN
is an acronym for Not-a-Number and represents that either a value is missing or the calculation cannot output any meaningful result.
None
is an object that represents no value.
scripting mode
is an offline mode of operation in which the user writes the commands to be executed in a text file (with .py extension for Python) which is then compiled or interpreted to run the program. Notes that Python interprets script on run-time and compiles a binary version of the program to speed up the execution time.
Sequential (data structure)
is an ordered group of objects stored in memory which can be accessed specifying their index, i.e. their position, in the structure.
SQL
or Structured Query Language, is a domain-specific language for managing data stored in a relational database management system (RDBMS).
SQLite
is a self-contained, public domain SQL database engine.
string
is a Python data type designed to store sequences of characters.
tuple
is a Python data structure designed to contain sequences of integers, floats, strings and any combination of the previous. The sequence is ordered and indexed by integers, starting from 0. Elements of a tuple can be accessed by their index but cannot be modified.